Numerical Analysis of Transient Temperature Field and Keyhole Geometry in Controlled Pulse Key-Holing Plasma Arc Welding

Abstract

A three-dimensional transient model is developed for numerical analysis of the temperature field, the weld pool, and keyhole shape during the controlled pulse key-holing plasma arc welding process. With considering the coupled thermal-mechanical actions exerted on the keyhole wall from the arc plasma, the periodic variation of the keyhole undergoing “establishing – expanding – contracting – closing” is numerically simulated in a pulse cycle. The computed accuracy is improved by accounting for the thermal-balance condition on the keyhole wall. The predicted keyhole sustaining period and fusion zones are in agreement with the experimentally measured ones.

Acknowledgments

The authors are grateful for the financial support for this research from the National Natural Science Foundation of China (Key Program grant no. 50936003).